Vehicle engines commonly utilize cooling assemblies to remove excess heat from the engine and maintain an optimal operating temperature. The cooling assembly pumps a coolant through the engine and other components in order to control engine temperature. Heat generated within the engine and other components is absorbed by the coolant and dispersed into the surrounding atmosphere through the use of a radiator. In order to improve dispersal by the radiator, it is common to utilize fan assemblies to draw or force air past the radiator to assist in temperature transmission.
It is not always desirable for such fan assemblies to be run continuously. At times, it is desirable for the temperature within the coolant to increase rather than decrease. Additionally, continuous operation when unnecessary places an non-required draw on the engine and thereby reduces efficiency. To compensate for this, present fan assemblies utilize fan clutch assemblies that allow for the selective engagement of the fan to the engine such that the fans are engaged only when necessary. The fan clutch assemblies may be operated in a plurality of configurations including hydraulic and air-pressure actuated. It is common for these systems to be biased towards fan operation such that when failure occurs in the clutch assembly, the fan continuously operates to keep the engine cool.
An issue with these fan assemblies and associated clutch assemblies stems from their location within the engine compartment. These assemblies must share space within the compartment with a variety of engine related systems. The assemblies, therefore, can be placed under severe dimensional restraints. However, fan clutch drives are commonly dimensionally constrained by the internal workings of the clutch which limits reduction of the drive assembly. This dimensional constraint, especially realized in clutch length and diameter, limits the applications wherein a pneumatic clutch can be utilized.
It would therefore be highly desirable to have pneumatic clutch fan assembly with a unique internal design wherein reduction in some of the external dimensions could be realized, along with corresponding reduction in material cost and weight. It would further be highly desirable for such a clutch assembly to provide optimal performance and operation while reducing or minimizing size and weight.